tests/ports/webassembly: Expand test for registerJsModule.

This tests `from mod import foo` where `mod` is a module registered using
the webassembly API `registerJsModule(mod)`, and where `foo` is a
JavaScript function.  Prior to the parent commit, this would fail.

Signed-off-by: Damien George <damien@micropython.org>

tests/ports/webassembly/register_js_module.js

@@ -1,6 +1,45 @@
+// Test the registerJsModule() public API method.
+
 import(process.argv[2]).then((mp) => {
     mp.loadMicroPython().then((py) => {
+        // Simple module.
         py.registerJsModule("js_module", { y: 2 });
         py.runPython("import js_module; print(js_module); print(js_module.y)");
+
+        // Module with functions.
+        // In particular test how "this" behaves.
+        py.registerJsModule("js_module2", {
+            yes: true,
+            add1(x) {
+                return x + 1;
+            },
+            getThis() {
+                return this;
+            },
+        });
+
+        console.log("====");
+
+        // Test using simple import.
+        py.runPython(`
+import js_module2
+
+print(js_module2.yes)
+print(js_module2.add1(1))
+print(js_module2.getThis())
+print(js_module2.getThis().yes)
+`);
+
+        console.log("====");
+
+        // Test using "from ... import".
+        py.runPython(`
+from js_module2 import yes, add1, getThis
+
+print(yes)
+print(add1(2))
+print(getThis())
+print(getThis().yes)
+`);
     });
 });

tests/ports/webassembly/register_js_module.js.exp

@@ -1,2 +1,12 @@
 <JsProxy 2>
 2
+====
+True
+2
+<JsProxy 3>
+True
+====
+True
+3
+<JsProxy 3>
+True